1. Field of the Invention
The present invention relates to electronic parts such as integrated circuit (IC) devices, and particularly to electronic parts with metal wiring having higher reliability e.g., the improved electromigration endurance, and manufacturing method thereof.
2. Description of the Related Art
Recently integration in memory IC devices represented by D-RAMs has been increasing. With the increase, wiring electrically connecting between elements becomes finer. This fineness requires wiring for a higher current density and operating temperature. At the same time, wiring is required for the further improved electromigration endurance, thereby attaining high reliability. However, the electromigration endurance is inversely proportional to a current density and operating temperature. At present, a thin film made of metal such as Al or Al alloys is frequently used for wiring. The electromigration endurance of such metal wiring has been improved by addition of a transition metal such as Cu or Ti in a trace quantity or the bamboo sheath-like grain structure (bamboo structure) which is caused by crystal grain growth. However, it is difficult to attain the reliability of wiring on the order of 0.1 micron only by this improvement in electromigration endurance. Recent investigations revealed that the electromigration endurance and stress-migration endurance due to tensile stress introduced in wiring were remarkably increased by a single-crystal wiring. As a means for attaining high reliability, it is considered that the crystalline properties of a metal thin film are as near to those of single crystal as possible.
At present, in electronic parts such as memory IC devices, metal wiring is formed on the surface of an amorphous thin film generally represented by a SiO.sub.2 interlayer insulative film with or without a barrier layer. Thus a metal thin film with the high crystalline properties cannot be formed by a so-called epitaxial crystal growth method where a single-crystal thin film can be grown by continuing the crystalline arrangement of an underlayer. As a result, metal wiring with the excellent electromigration endurance and high reliability is hardly obtained.
As described above, there is a problem that conventional electronic parts hardly have metal wiring with the high reliability.